The present invention relates to solid-state imaging apparatus using MOS imaging device in which high image quality is made possible by suppressing fixed pattern noise.
Generally in MOS imaging device, a fixed pattern noise (FPN) occurs due to dark current components of pixel or variance in amplification transistor of pixel. Various methods have been proposed as a method for suppressing the fixed pattern noise. For example, CQ Shuppan-Sha (publisher), Basics and Application of CCD/CMOS Image Sensor (pp. 193 to 194) shows a fixed pattern noise suppressing method as will be described below. In particular, as shown in FIG. 1, signals from CMOS image sensor 101 shielded from light are subjected to A/D conversion at A/D converter 102 and are previously stored as reference signal in a frame buffer 103. At a subtracter 104, then, the reference signal stored at the frame buffer 103 is subtracted from image signal outputted from the CMOS image sensor after exposure/accumulation so as to remove/suppress the fixed pattern noise.
Further, besides normal XY-addressing read method, also known as a read method of MOS imaging device is a concurrent shutter (also referred to as global shutter) type read method where exposure period is uniform for all pixels.